What Palin is making reference to is a story that was reported two day ago in which Hillary once made a reference to Palin in a 2015 interview and her team decided that it was beneath her to do so.
Courtesy of The Hill:
In an interview with Times Magazine journalist Mark Leibovich last July, Clinton reminisced about spending time in Alaska during one summer in college, where she came face to face with “a huge moose.”
“I've eaten moose, too. I've had moose stew,” Clinton told the magazine, according to a transcript made public from the hacked email account of Clinton's campaign chairman, John Podesta.
“In Alaska, moose stew. So that's why I always got a big kick out of Sarah Palin with all of her, ‘We're cooking up some moose stew here,’” she added, with a laugh.
Clinton’s presidential campaign later asked Leibovich not to include the reference to Palin.
“Fine to use the moose, but appreciate leaving the mention of Sarah Palin out,” Clinton spokesperson Jennifer Palmieri told the journalist in a July email made public on Tuesday.
So in a nutshell Hillary made some off the cuff reference to Sarah Palin, and her people realized that the freak show would use it as a chance to dance around shouting "Look at me, look at me, I am still relevant, even Hillary Clinton is talking about me."
And of course, as this demonstrates, that is exactly what she did.